Top Crankshaft for scooters with 50cc Piaggio 4-stroke engines. The crankshaft corresponds to the original in design and is ideal as an inexpensive replacement part. This crankshaft was used in the recent 2003 series and for all subsequent model years and features a 20mm ID crank bearing on the belt side. Matching crankshaft bearing set: 38331 OEM number for comparison: 969428